Motor controller



March 18 1924. Q v 1,437,422

- C. W. YERGER MOTOR CONTROLLER Filed June 23 1919 I N 'VEN TOR.

ATTORNEY Patented Mar. 18, 1924;

, UNITED STATES 1,487,422 [PATENT OFFICE.

Om W. mm, 01 HILWAU KEK'WISCONSIN, ASSIGNOR TO THE CUTLER-HAM- m BIG. (70., 0! MILWAUKEE, WISCONSIN, A CORPORATION 01 WISCONSIN.

MOTOR CONTROLLER.

Application filed June 23, 1819. Serial No. 805,985.

To all whom it may concem.

Be it known that I, Cmintns a citizen of the United States, Milwaukee, in the county o and Stats of Wisconsin, have and u ui Improvements or? which the iollo r choc being had to the accompar ft aning apart of this s p This invention relates to improv motor controllers.

In my prior application Serial No 2Z9fi7fi. filed February" 28, 1919, there is disclosed a method of utilizing a number of switchcs to. affect a relatively greater number of steps of: control and the present invention has among its obiiccts to providc a controllcr of the so-ca led multiple switch type for controlling an electric motor in. accord ance with such method,

Another object is to provide a controller of the aforesaid type with means insuring against operation of the several switches except in the desired sequence.

Another object is to provide a controller of the aforesaid character affording low voltage protection.

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawing schematically and diagrammatically illustrates one embodiment of the invention which will now be described, it bein I understood that the invention may be em died in other forms falling within the scope of the appended claims.

Referring tothe drawing, the same illustratesa controller comprising four separately operable switches 1 to 4 to control an electric motor M through the medium of three resistance sections r, r and r in such a manner as to afford six steps of control. The. motor M is shown as rovided with an armature a and' series fie d i but it is to be understood that the motor might be of other t pesl Each of t eswitches 1 to 4 is provided with a laminated brush 5 "to bridge a pairof. stationary contacts 6 and 7 and the power connections are such that u n closure of switch 1 circuit is completed m line L through said switch, by conductor 8 through resistances r, r and r" in series by conductor 9 through the motor armature and series ncnts in field to line L"; Upon closure of switch 2 circuit is completed from line L through said switch by conductor 10 to a point hetvvsen resist nccs rand r" short ormcr resistance nit is co.

by stand es r his rasistancc M 3 suc I. t e steps of switches i 9 of switch 41- ductcr Til 1th and throng s dnctor conductor resistances r and r his: cont-rel. Further tho con that reclosure of switch 1 compiotss circuit from line L by conductor 8 resist ance r, by conductors 10 and through switch 1- to conductor 9, thus paralleling re sistance r with resistances r and r for a further step of control, while oi switch 2 completes circuit from line L through said cwitchby conductor 12 through switch 4 and by conductors l3 and 9 direct l to the motor thus throwing the motor irisctly on the line as a final step of contro For simplicity of illustration each of the switches is shown as comprisin a pivoted arm having a rigidly connected-operating handle 14, although in practice it is pro ferred to employ switches of the type shown in the patent to T. E. Barnum 959,910, of May 31, 1910. Also, for simplicity of illustration, the switches are shown as interlocked by the means new to be described, although in practice it is preferred to follow more closely the design of the interlocking means shown in said Barnum atent. As shown, the switch 2 is, provi ed with a laterally extending in 15 and -a co-operating cam 16 carried y a rock shaft 17, said cam being normally disposed, in the path of said in to prevent closure of said switch while t 6 switch 1 is provided with a laterally extending pin 18 adapted to 00-0 'rate with a lug 19 on said rock sha to withdraw the cam 16 from the path of pin 15 when switch 1 is moved to closed position, This insures a 'nst closure of switch 2 until after c osure of switch 1 and switches 8 and 4 are similarl interlocked whereby closure of switch 4 is prevented until after closure of switch 3. Also, switch 3 is normally locked in open position by a sliding bar 20 extending across the ath of a lug 3 on said switch, said bar ing connected to a bell crank lever 21 operable by an extension 2 of switch 2 to release switch 3 upon closure of switch 2. Thus closure of switch 4 is rendered dependent upon prior closure of switch 3 wh1le closure of switch 3 is rendered dependent upon prior closure of switch 2, closure of switch 2 bein in turn rendered dependent upon prior 0 osure of switch 1 which insures against closure of said switches except in the order of their reference numerals. When switches 1 and 2. are opened as above set forth following closure of switch 3, reclosure of switch 2 is again rendered dependent upon prior closure of switch 1 whereby the above described desired sequence of operation of the switchcs is positively insured. In this connection it is to be noted that the interlock between switches 2 and 3 in no wise interferes with the opening of switches 1 and 2 following closure of switch 3.

While in practice the switches might if desired be arranged to remain closed, until forcibly opened, each is preferably biased to return to open osition and rovided with means to lock tie same in c osed position subject to release upon failure of voltage. To this end switches 2 and 4 are respectively provided with retaining magnets 22 and 23, while switches 1 and 3 are rovided with mechanical locking means un er the control of switches 2 and 4 respectively. More specifically, the interlocking lugs 19, associated with switches 1 and 3, are each pro vided with a hook 24 to engage the pin 18 of its respective switch, sai hooks being thrown into engagement with said pins by pressure of the pins 15 of switches 2 and 4 against the cams 16 upon closure of the latter switches. Thus in o ration switch 1 is mechanically locked in c osed position upon closure of switch 2, the latter switch being held closed by magnet 22 while switch 3 is mechanically locked in closed position upon closure of switch 4, the latter switch being held closed by magnet 23. However the circuit arrangement is such that energization of magnet 22 is rendered de )endent upon closure of switch 4, which as auxiliary contacts 4 in circuit with said magnet while energization of magnet 23 is rendered dependent upon closure of switch 1 which has auxiliary. contacts 1 in circuit with said magnet. Accordingly, assumin hand over. hand 0 eration of the switches 1n the order above escribed, the switch 2 is left free to open when the operator releases the same to gras the switch 4 and said switch 2 in opening releases switch 1 whereas upon closure of switch 4 and subsequentreclosure of switches 1 and 2, the latter switch is held closed by magnet 22. Moreover, switch 4 must be manually held closed until switch 1 is reclosed to energize magnet 23 and switch 2 must then be closed to hold switchv 1 in closed position. This provides for release of all switches in the event that the full sequence of operations is not completed and thereby insures against leaving any portion of the resistance in circuit.

The circuit of magnet 22 extends from line L throu 11 said magnet, by conductors 25 and 26 t rough the auxiliary contacts 4 of switch 4, by conductor 27 to line L, while the circuit of magnet 23 extends from line L by conductor 28 through the auxiliary contacts of switch 1, by conductor 29 through said magnet to conductor 26 and thence to line L as described. Both magnets are thus connected across the line whereby they are subject to de-energization u n failure of voltage to thereby release all bf the switches.

While the controller illustrated is provided with only four switches it is to be understood that the same'may be provided with additional switches where control of additional resistance sections is desired. Also, it is to be understood that the low voltage magnets may be subjected to push button or overload control in the known ways and it is to be noted that the controller is particularly adapted to such overload control since the motor circuit is finally broken thereby at three points.

What li -claim as new and desire to secure to secure by Letters Patent is:

1. In a motor controller, in combination, a plurality of manually operable switches to be operated in a definite sequence includin closure and reclosure of certain thereof, an interlocking means providing against 0 eration of said switches except in such de nite sequence.

2. In a motor controller, in combination, a plurality of manually operable switches to be operated in a definite sequence including opening of certain of said switches followin closure of other of said-switches and en sequent reclosure of said certain of said switches, and interlocking means for said switches for preventing operation thereof except in said definite sequence.

3. In a motor controller, in combination, a plurality of manually operable switches biased to open position, said switches having meansrequiringthe same to be closed in a definite order and permitting certain of said switches to be 0 ned and reclosed after closure of other 0 the same and means for restraining certain of said switches in closed position but only after completion of the aforesaid operations thereof.

4. In a motor controller, in combination,

too

III

Ill

- and reclosed a plurality of manually a plurality of manually biased to open position, sai switches having means requiring the same to be closed in a definite order and permitting certain of said switches-to be opened and reclosed after closure of other of the same and means for certain of said switches in closed pgsition, closed in'a de ite order, means for re-' said switches in closed straining certain of for restraining thereposition and. means mainder of said switches in closed position,

said first mentioned means having means rendering the same inefi'ective to so function until after closure of one of said last mentioned switches whereby certain of the previously closed switches may be opened after closure of other of the same.

6. In a motor controller, incombination, a plurality of manually operable switches biased to open ition, said switches to be closed in a de nite order, means including a m t for retaining certain ofsaid switches in closed position and means including a low voltage magpet for holding the remainder of sai switc es in closed position, and rendering energization of said first mentioned magnet e ndent upon prior closure of one of said ast mentioned switches, to thereby permit opening and reclosure of certain of said switches after closure of other of the same.

7. In a motor controller, in combination, a plurality of manually biased to open position and means necessitating closure of said switches in a definite order and retaining the same in closed sition but permitting certain of said switc es to be opened and reclosed after closure of other of the same.

8. In a motor controller, in combination, operable switches biased to open position, mechanical interlocking means for said switches necessitating closure thereof in a definite sequence and providing for retention of certain of said switches in closed position by other of said switches and separate retaining ma ets for the last mentioned switches, one 0 said retaining magnets being dependent for energization ugon closure of the switch held closed by t 0 other magnet, to permit certain of said switches to be opened and reclosed after closure of another of said 9. In a motor controller, in combination,

a plurality of switches biased to open po-,

o rable switches "switches in a operable switches sition, means necessitating closure of said definite order,-said means including means for holding certain of said switches closed when other of said switches are closed, and electro-responsive means for holding certain of said switches closed when other of said switches are closed.

10. In a motor controller, in combination, a plurality of pairs of switches biased to open position, said switches to be closed in a definite-"order, means associated with one switch of each air for holding the other switch in closed position, and electro-responsive means controlled by one pair of switches for holding anotherpair of switches in closed position.

11. In a motor controller, in combination, a plurality of groups of switches, means necessitating closure of said switches in a definite order and opening of the switches of each group in a definite order while permitting opening of the switches of one group when the switches of another group are closed, and separate electromagnets for holding a plurality of said switches in closed osition.

12. n a motor controller, in combination, a plurality. of groups of manually operable switches biased to open position, means necessitating closure of said switches in a definite order, means necessitating o ening of the switches in each group in a efinite order with respect to each other, means permitting opening of all switches in each group irrespective of the position of the switches in another group, and means for restraining all of said switches in closedposition when all of said switches have been closed.

13. In a motor controller, in combination, a plurality of roups of manually operable switches biase to open position, means necessitatin closure of said switches in a definite or er, means associated with one switch of each group for restraining the other switches 0 that group in closed position, electro-res onsive means associated with a switch o one group for holding another group of switc es in closed position, and electro responsive means associated with said last mentioned group of switches for holding said first mentioned group of switches in closed position.

14. In a motor controller, in combination, a plurality of groups of manually operable switches biase to open position, means necessitating closure of said switches in a definite order, and electro-responsive means controlled by one switch in each group for restraining another group of switches in closed SltlOIl.

In witness whereof, I have hereunto subscribed my name.

CHARLES W. YERGER. 

